accessing session variables when we use sendRedirect

Hi, I have a servlet class XXXX in one web module of serletContext A. This servlet does the required business logic and stores the values in session and redirects the request to the JSP page YYYY. My JSP page is present in different module of same servletContext A. My code is working fine and i'm able to retrieve the session values from JSP page. My understanding from this is,we can share the session between different modules of the same ServletsContext but we cannot share the session between two different servletContext.I would like confirm this.Please correct me,if I'm wrong.